Process for crimping yarn



J. JOLY PROCESS FOR CRIMPING YARN March 19, 1 968 2 Sheets-Sheet 1 Filed March 27. 1964 I In venlor Team 35/ A llorneys March 19, 1968 J. JOLY 3,373,470

PROCESS FOR CRIMPING YARN Filed March 27, 1964 2 Sheets-Sheet 2 Inventor w -fIfean B O/y w /z4/, Attorneys United States Patent ()fiFice 3,373,470 PROCESS FOR CRIMPING YARN Jean Joly, Lyon, France, assignor to Societe Rhodiaceta, Paris, France, a corporation of France Continuation-impart of application Ser. No. 171,521, Feb. 6, 1962. This application Mar. 27, 1964, Ser. No. 355,379 Claims priority, application France, Feb. 8, 1961, 852,055 13 Claims. (Cl. 28-72) This application is a continuation-in-part of application Serial No. 171,521, filed Feb. 6, 1962, now abandoned.

Many processes have been conceived for modifying the appearance and feel of synthetic yarns. Thus, it is Well known to produce such yarns in the form of continuous filaments, which have the disadvantage, for a number of applications, for example in clothing, that they lack bulk and have insuflicient covering capacity.

Their conversion into cut fibre, which is spun by the usual methods of the textile industry, only partially resolves the problem and often gives rise to a further disadvantage, that of pilling. It is for this reason that processes for crimping or texturing continuous filaments have been so extensively developed.

The oldest method consists in subjecting such filaments to an overtwist, which is set, generally by a thermal treatment, and then to an untwisting, these successive operations being carried out continuously if the falsetwist process is employed.

In another method, a heated yarn is passed over a knife-edge along an acute-angled path, of which the apex is situated at the knife-edge.

It is also known to produce bulky yarns having loops, by passing a mnltifilament yarn through a current of compressed fluid actuated with a whirling movement.

Finally, another known method of crimping continuous yams, known as stufier crimping, consists in stufiing the yarns under pressure in a confining crimping chamber provided at its outlet with a tiltable or hinged flap or other counterpressure device, the deformations obtained being set by thermal treatment, usually within the crimping chamber.

These four types of processes have all received industrial application on a varying scale.

The stufier crimping process has the advantage that it gives a high-bulk yarn having no loops (which often give the made-up articles a rough feel) and of which the elasticity, which is appreciably lower than that of yarns treated by the first two processes above referred to, is very suitable for the production of many articles of clothing, notably sweaters. However, the present industrial application has the disadvantage that it gives a yarn whose filaments have an inphase crimp and which in addition possesses irregularities in dyeing aflinity.

For the practical application of this process, the yarn is introduced with the aid of a pair of rollers into a crimping chamber in which it becomes accumulated until its pressure is sufiicient to overcome the pressure of the counter-pressure device preventing it from leaving the chamber. The apparatus employed comprises a number of moving mechanical parts, which is always a disadvantage when it is desired to operate at high speed.

It is an object of this invention to provide an improved crimping process.

According to this invention, there is provided a process for stutter crimping of thermoplastic filaments in which the filaments are introduced into an enclosed space with the aid of a current of fluid under pressure and at a temperature suflicient to set the filaments and in which the filaments are, under the action of the fluid, packed 3,373,470 Patented Mar. 19, 1968 under pressure into said enclosed space and forced therethrough, a part of the fluid being allowed to escape laterally in a controlled fashion through orifices in the wall of the enclosed space.

The process of this invention may be carried out by a very simple apparatus comprising no moving mechanical parts and enables thermoplastic filaments to be crimped at a high speed, which may reach or even exceed 1000 m./min.

According to a further aspect of this invention, there is provided stufi'er crimping apparatus comprising an injector having therethrough a passage for filaments, means for supplying heated fluid under pressure to said injector and in a direction to carry filaments through said injector passage, and a tubular crimping chamber communicating with said injector and having orifices at least in a central portion of the chamber wall.

The invention further concerns the crimped filaments obtained by means of the process and apparatus of the invention. Such filaments have more especially the advantage of a high-bulk crimp free from in-phase waves between the various filaments, and a much more regular dyeing afiinity than yarns produced by the usual methods of stuffer crimping.

By filaments are understood both single continuous filaments and groups of continuous filaments or short fibres, for example tows, yarns and groups of yarns, composed of filaments having the same or difierent count, cross-section or composition. These filaments may come directly from the spinning machine or they may have undergone any preliminaryv treatment which does not interfere with the present process. They may have been, for example, crimped by another method, dyed, assembled by a slight twist not exceeding 50 turns per meter and preferably less than 20 turns per meter or twisted with higher twists, of the order of turns per meter for a yarn of, for example 500 deniers.

The process according to the invention is applicable to all thermoplastic filaments having sufiicient strength to withstand without breaking the action of the current of fluid. Such filaments are, more especially, artificial and synthetic filaments based upon cellulose acetate and triacetate, polyamides, polyesters, polyolefins, polyacrylonitrile, polyvinyl derivatives, etc. Of course, the operating conditions, the temperature and the pressure of the heating fluid depend upon the nature of the filaments, their count and also their speed of travel, it being understood that the temperature applied must be such as to set the filaments under the operating conditions employed. If the speed of travel of the filaments is sufficiently high, temperatures higher than the melting point of the filaments may be employed.

As has been stated, it is possible by means of this process to work at speeds of up to 1000 metres per minute and more, which afford the possibility, for example in the case of synthetic filaments, of continuously crimping them subsequently to the stretching which they normally undergo in the course of their production.

When several yarns are simultaneously introduced into the apparatus according to the invention, their speed of supply may be identical. In this case, there is obtained a crimped assembly, in which the number of filaments is the sum of the number of filaments of the yarns introduced into the chamber.

It is thus possible to obtain with a number of yarns crimped assemblies of large count without these yarns having to be assembled.

It is also possible to dissociate the assembly obtained into its various constituents. In contrast to what might have been expected, this dissociation takes place without difiiculty, and it is thus possible, with one adjustment of the apparatus, to prepare crimped yarns of different counts, which is another unexpected result.

If the speed of supply of the various yarns to be crimped is different, a fancy yarn of the chenille type is obtained, a yarn introduced at the lowest speed constituting the core yarn and the others the effect yarns.

These fancy yarns have various advantages over yarns of the known type which have long been known:

They comprise no binding thread.

The insertion of the loops of the effect yarns into the loops of the core yarn is effected in all directions.

In order to prepare these fancy yarns, it is possible for the introduction of the yarns which are to form the effect yarns to be carried out at at least twice the speeds of that of the yarn which is to form the core yarn.

As has been stated in the foregoing, the yarns to be crimped may be of identical or different natures. In the case of the preparation of a fancy yarn, for example, a polyamide yarn may be employed to form the core and an acetate yarn to form the effect yarn.

It is also possible to effect by this process the crimping of tows, even having a high total count, which consist of thermoplastic filaments. The tows to which the process of the invention is applicable are those consisting of thermoplastic filaments of any nature, whether artificial or synthetic, and such in particular as those based upon cellulose acetate or triacetate, polyamides, polyesters, polyolefines or polyacryl or polyvinyl derivatives.

These tows may optionally comprise a proportion of non-thermoplastic filaments.

The total count of these tows may vary between wide limits and may reach 200,000 deniers. It will generally be between 20,000 and 100,000 deniers.

The count of the filaments constituting the tow may be small, of the order of 1.5 denier or less, or much higher, for example, 40 deniers.

The crimping treatment according to the invention may be applied to a tow already cn'mped by a conventional method; the bulk is thereby further increased.

The fluid employed may be, for example, hot air or, preferably, steam, under pressure.

It is possible to carry out the dyeing of the filaments simultaneously with their crimping, by impregnating the filaments with a dyeing bath before they come into contact with the current of fluid under pressure.

This impregnation may be effected by any known means. The filaments wound on a support may be discontinuously impregnated with a dyeing bath and, after squeezing to the desired extent, the filaments may be driven by the current of fluid through the enclosed space in which the crimping is carried out. In a continuous process, the filaments may be brought, before being subjected to the action of the fluid, into contact with a device which deposits the said bath point by point over the entire length of the filaments. This method of operation is suitable especially when the crimping takes place continuously after the stretching in the case of synthetic filaments. The filaments may be, for example, brought into contact with a roller rotating in a vat containing the dyeing bath.

The action of the hot fluid ensures, simultaneously with the crimping and the setting of the filaments, a rapid penetration of the dye into the interior of the latter.

Instead of a gaseous fluid such as hot air or steam under pressure, as indicated above, use may be made of a liquid which may, for example, be water at a temperature of 80-160 C. under a pressure of about 0.5 to 7 kg./cm. or if a particular additional effect is required, a liquid exerting on the filaments a swelling, setting, dyeing or other action.

There will hereinafter be described by way of example one embodiment of apparatus according to the invention by means of which it is possible to carry out continuous crimping. In this apparatus, the injector, which is a simple device for the introduction of the filaments, may be of any type and does not require any particularly accurate adjustment. The tubular chamber through which the filaments thereafter passes may comprise, first a simple tubu lar passage having imperforate walls, to which is connected a coil spring, of which the controlled extenison makes it possible to adjust the dimensions of the orifices through which the heated fluid laterally escapes. By application of a lateral force to the outlet end, the latter can be readily curved to the desired extent for obtaining optimum pack- This embodiment is illustrated in the accompanying drawings in which:

FIGURE 1 is a diagrammatic sectional view of the apparatus of this embodiment;

FIGURE 2 is a diagrammatic view illustrating the apparatus of FIGURE 1 amplified to enable the yarn to be dyed simultaneously with the crimping; and

FIGURES 3, 4 and 5 illustrate three yarns crimped using the apparatus of FIGURES 1 and 2.

Referring to FIGURE 1, the numeral 1 denotes an injector, into which yarn F is adapted to be introduced. The injector 1 comprises a nozzle 2 having therethrough a passage 2' and a pipe 3 into the end of which the nozzle 2 is screwed, the pipe 3 having an outlet 3 surrounding the outlet of the nozzle passage 2'. Heated fluid under pressure, in this example, steam is adapted to be passed through the pipe 3. At the outlet of the pipe 3 is located a conduit 4 having a passage 4' therethrough and an enlarged extension 7 provided with a permeable wall. Within this extension is fitted a metal spring 5 having gaps 6 between the convolutions thereof. In use of this apparatus, yarn is propelled, by the action of the fluid, from the nozzle 2 and through the tubular passage 4 in the conduit 4 and then into the interior of the spring 5. The spring 5 is curved at its outlet end to an arc of radius R and length l and having an angle a at the centre.

Some of the fluid, e.g., steam, escapes from the spring, for the greater part through gaps 6 between the convolutions. The permeable wall 7 canalises the steam escaping through the convolutions of the inlet end of the spring thus contributing to an increase in their temperature.

The yarn is tightly packed in the spring 5 into a compact mass which leaves the outlet end of the spring in the form of a wad 8, which can be collected as such, or subjected to tension, and the yarn wound on to a bobbin.

FIGURE 2 illustrates the above described apparatus amplified for carrying out the dyeing of the yarn simultaneously with crimping. The additional parts are a supply roller 9 and an auxiliary roller 10 therefor, an applicator roller 11, a dye bath trough 12 and a belt conveyor 13. In use of the amplified apparatus, yarn F coming, for example, from a stretching device (not shown) is taken up by the supply roller 9 and then passes over the applicator roller 11 which dips in the trough 12 containing the dyeing bath. It is then introduced into the injector and into which steam V is injected through the pipe 3. The yarn becomes packed in the space within the spring 5 consisting of a metal spring and the wad 8 leaving the spring is collected on the belt conveyor 13.

The apparatus just described does not constitute the only possible form of construction according to the invention, and it will be appreciated that many modifications may be made within the scope of the claims.

There are summarised in the following Table I the results obtained in a whole series of tests carried out with the aid of the apparatus of FIGURE 1, in which the temperature and the pressure of the fluid, in these tests, steam, passed into the injector, and the speed of travel of the yarns were varied.

In all these examples, an injector 1 was employed in which the pipe 3 for the introduction of steam possessed an internal diameter of 5 mm. The passage 2 through which the yarn was supplied had an internal diameter of 10 mm. at its inlet end and one of 2 mm. at its outlet end, at which its external wall had the form of a frustum of a cone having an angle at the apex of 53. The outlet orifice of the pipe 3 of the injector had an internal diameter of 3 mm. and the wall around this outlet orifice had the form of a frustum of a cone having an angle at the apex of 66. The length of the tubular passage 4' was mm.

In Examples 1 to 12 and to 20, the tubular passage 4' and the spring 5 had an internal diameter of 10 mm. and the spring had a length of 110 mm. The angle on as indicated in FIGURE 1 was about In Examples 13 and 14, the tubular passage 4' and the spring 5 had an internal diameter of 8 mm. The spring was substantially rectilinear and its first convolutions were so stretched that its total length was about 103 mm.

In Examples 21 to 23, the internal diameter of the tubular passage 4' and of the spring 5 was 8 mm. and the length of the spring was 100 mm. The angle a was about With regard to the nature of the treated yarns, the abbreviations used have the following meanings:

PA-polyhexamethylene adipamide.

PEpolyethylene terephthalate.

PP-polypropylene.

(The figures appearing after thesesymbols indicate in der a pressure of 3 kg./cm. The temperature within the injector was of the order of 180 C.

A wad of crimped yarn having a pale blue colour was collected on the belt conveyor. The fastnesses of the dye obtained was similar to those obtained by the conventional dyeing methods.

The following Table H gives the results obtained in a series of tests with the aid of the apparatus of FIGURE 1, using hot water under pressure as the fluid. The temperature, the pressure and the rate of flow of the water passed through the injector were varied, as also was the speed of travel of the yarn.

In all of these examples, an injector identical to that of Examples 1 to 23 was employed.

In Examples 25 to 30, the tubular passage 4' and the spring 5 had an internal diameter of 8.5 mm. and the spring had a length of mm. The angle a was In Examples 31 to 34, the internal diameter of the tubular passage 4' and of the spring 5 was 6.5 mm. and the length of the spring was 38 mm. The angle a was 60.

The yarn treated was in each instance a polyhexamethylene adipamide yarn.

(The figures indicate the count and the number of filaments of the yarn.)

TABLE II Speed of Pressure Temperature Fluid Production, Example No. Nature of the Yarn the Yarn of Fluid of the Fluid Discharge g./h. nozzle (m./m1n.) (kg/om!) C.) (gm./rm'n.)

25 840/14 190 3 144 600 1, 064 26.. 840/ 1. 5 127 240 812 27.. 1040/60 TrilobaL 165 1. 5 127 920 1, 144 28.. 620/30 Trilobal- 305 2 134 315 1, 057 29... do 1 121 750 540 30 450/30 Trilobel. 280 4 152 450 840 31 do 200 1. 5 127 700 600 150 1 121 630 630 330 3 144 400 l, 386 355 3. 5 148 350 938 each instance the count of the yarn and the number of filaments in the yarn.)

TABLE I Speed of the PfreFslsur; T?l?;lfijeligltul Prodlhtitlml, E 1e No. Nature of the Yarn am, 0 ui o e ui g.

xamp mJmin. (kg/cm?) 0.) nozzle A T 11 b 1840 60 200 7 168 1 120 i P .do o a I 200 2 1:120 3 o 200 2 215 1, 120 4 in 200 2 270 1, 120 5 d 500 8 175 2,800 6 as A T 11 bal 1040 60 420 5 P it? as 800 9 PA f o d 6 0/30 600 3 gg 9S8 PA Round Cross-section 840/60 200 3 12 PA Trilobal 1050/60.; l, 000 10 195 7,000 13 do 200 5 160 1,400 14 do 200 2 225 1,400 15 PA Round Cross-section 840/140 160 7 896 16 -d 620 8 2,915 17 n 1, 000 5, 288

2 115 1g PA Eound Cross section 900/ 76 0 7 168 0 20 200 2 280 800 21 500 4 210 2,130 500 2 175 2, 000 1, 000 3 4, 000 The following example is given of the simultaneous The following tables set out the results obtained by dyeing and crimping of a yarn.

Example 24 There was employed a bright polyhexamethylene adipamide yarn having a count of 840 deniers/60 filaments, of trilobal cross-section which, coming from a stretching device, was passed through the apparatus illustrated in FIG- URE 2.

The injector employed was the same as that in Examples 1 to 23. The tubular passage 4' and the spring 5 had an internal diameter of 8 mm. The spring had a length of 100 mm. The angle a was 30.

The trough contained an aqueous bath containing 5 grams per liter of Acid Blue 77 (Colour Index, 2nd edition, vol. I, pape 1264), and having a pH of 4.

The yarn was introduced into the nozzle at a speed of 200 meters per minute, while the; steam was injected unsimultaneously introducing a number of yarns into an apparatus according to the invention.

In Table III of the various yarns to be crimped are supplied at the same speed and collected in the form of a crimped assembly.

In Table IV, the yarns are supplied at the same speed into the injector, but are separately collected after crimpmg.

In Table V, the yarns are supplied at different speeds. The yarns obtained are fancy yarns of the chenille type.

The abbreviations appearing in the tables have the following meanings:

PApolyhexamethylene adipamide.

PPpolypropylene.

Peethylene polyterephthalate.

Art-cellulose acetate.

(The numbers appearing after these symbols, or in the column composition, indicate in each instance the count in deniers and the number of filaments in the yarn.)

Vspeed of supply of the yarn in m./ min.

p-pressure of the fluid sent into the injector in kg./cm.

ttemperature of the fluid sent into the injector.

p--pressure in kg./cm. of the fluid (steam) sent into the injector.

ttemperature of the fluid (steam) sent into the in jector.

V-speed of supply of the tow to be crimped in meters per minute.

FIGURE 3 illustrates the yarns of Example 40 undergoing separation. These yarns are thereafter separately collected.

With regard to the nature of the tows treated, the meanings of the abbreviations are as follows: PApolyhexamethylene adipamide.

TABLE V Yarns to be Crimped Fluid Example VA VB VC No. Yarn A Yarn B Yarn C Nature p 1;

FIGURE 5 illustrates the yarn obtained in accordance with Example 44.

FIGURE 4 illustrates the fancy yarn obtained in accordance with Example 47.

Table VI sets out the results obtained by introducing different tows into the apparatus according to the invention. The nature of the tows to be crimped, the total PPpolypropylene.

Accellulose acetate.

T.Accellulose triacetate.

The counts are expressed in deniers.

The acetate tows employed in Examples 57 and 58 were pre-crimped by packing in a compression chamber.

TABLE VI Material Manufacture of the Results,

Crimped Tow production Example No. in kgJmin. Nature of Total count Count of the V p t by injector the tow of the tow filaments count of these tows and the count at the fibre of the filaments, as also the operating conditions, have been varied. The abbreviations appearing in the table are the following:

The crimped tows obtained by the process of the invention may be employed for various purposes. In particular, they may be converted by methods known per se into discontinuous filaments which may be used either pure or blended with other natural, artificial or synthetic filaments.

I claim:

1. A process for stuffer crimp ing thermoplastic filaments, such process comprising introducing the filaments to be crimped into one end of an elongate confined space by means of a current of fluid under pressure and at a temperature sufficient to set the filaments, tightly packing said filaments into said confined space by controllably releasing part of said fluid from said confined space laterally of the confined space at a position spaced from the other end of said space and forcing the packed filaments through said space to said other end thereof under pressure by the remainder of said fluid.

2. The process specified in claim 1, in which the said fluid is steam.

3. The process specified in claim 1, in which the filaments are impregnated with a dyeing solution before being introduced into said enclosed space.

4. The process specified in claim 1, in which the said fluid is a liquid.

5. The process specified in claim 4, in which said liquid is water.

6. The process specified in claim 4, in which the liquid is chosen to react on the filaments.

7. A process for stufier crimping thermoplastic filaments, such process comprising heating a fluid to a temperature high enough to set the filaments to be crimped, passing said fluid into one end of an elongate confined space under pressure introducing the filaments to be crimped into said confined space by entraining the filaments in said fluid, tightly packing said filaments into said confined space by controllably releasing part of said fluid from said confined space laterally of the confined space at a position spaced from the other end of said space and forcing packed filaments through said space under pressure by the remainder of said fluid.

8. The process specified in claim 1, in which the filaments are introduced into said elongate confined space as a plurality of multifilament yarns.

9. The process specified in claim 8, in which said yarns are disassociated after crimping.

10. The process specified in claim 8, in which the said yarns are introduced into said elongate confined space at different speeds.

11. The process specified in claim 10, in which said yarns are composed of filaments of different compositions.

12. A process for stuffer crimping thermoplastic filaments, such process comprising introducing the filaments to be crimped into one end of a confined space by means of a current of fluid under pressure and at a temperature sufiicient to set the filaments, causing the said filaments to fold and crimp by pressing against a mass of crimped fibres already in said confined space by controllably releasing part of said fluid from said confined space laterally to the latter at a plurality of positions spaced from the other end of the confined space, and forcing the folded and crimped filaments through said space to said other end thereof under pressure by the remaining fluid.

13. A process for stufier crimping thermoplastic filaments, such process comprising heating the filaments in an enclosed zone to an elevated temperature sufiicient to set the filaments by entraining the filaments in a current of heated fluid under pressure passed into said zone, ejecting said heated filaments into a crimping zone by causing said current of fluid to pass into said crimping zone, causing the filaments to be folded and crimped against a mass of crimped fibres already in said crimping Zone by releasing part of said fluid laterally from the crimping zone, and forcing the crimped filaments along an extension of the crimping zone to a discharge end thereof under pressure of the remainder of said fluid.

References Cited UNITED STATES PATENTS 2,569,700 10/1951 Stalego 57-34 3,055,080 9/1962 Claussen et a1. 28-72 3,093,867 6/1963 Chandler 28-75 X 3,099,064 7/1963 Haynes 56-34 3,099,594 7/1963 Caines et al. 28-1 3,103,731 9/1963 Salyer et al. 57-34 2,914,835 12/1959 Slayter 28-72 2,917,806 12/1959 Spence et al. 28-72 2,854,729 10/1958 Russo et al. 28-1 2,949,659 8/1960 Heijnis 28-1 3,036,357 5/1962 Cook et al. 28-72 FOREIGN PATENTS 636,054 2/ 1962 Canada.

1,264,506 5/ 1961 France.

LOUIS K. RIMRODT, Primary Examiner. 

1. A PROCESS FOR STUFFER CRIMP ING THERMOPLASTIC FILAMENTS, SUCH PROCESS COMPRISING INTRODUCING THE FILAMENTS TO BE CRIMPED INTO ONE END OF THE ELONGATE CONFINED SPACE BY MEANS OF A CURRENT OF FLUID UNDER PRESSURE AND AT A TEMPERATURE SUFFICIENT TO SET THE FILAMENTS, TIGHTLY PACKING SAID FILAMENTS INTO SAID CONFINED SPACE BY CONTROLLABLY RELEASING PART OF SAID FLUID FROM CONFINED SPACE LATERALLY OF THE CONFINED SPACE AT A POSITION SPACED FROM THE OTHER END OF SAID SPACED AND FORCING THE PACKED 